Sir Karl Raimund Popper

Popper, Sir Karl Raimund, 1902–94, Anglo-Austrian philosopher, b. Vienna. He became familiar with the Vienna circle of logical positivists (see logical positivism) while a student at the Univ. of Vienna (Ph.D., 1928). He taught at Canterbury Univ., New Zealand (1937–45), and then at the London School of Economics, retiring in 1969. Popper's thought develops from his view of knowing as an individual, unpredictable act of genius, not acquired by induction, as empiricists hold, nor limited to verifiable statements, as the logical positivists hold. Like the logical positivists, Popper worked with the distinction between scientific knowledge and pseudoscience, but he understood the two to be related as well as distinct: pseudoscience or "myth," as he sometimes termed it, can inspire or grow into science, or overlap with it (as in the case of psychology). He rejected the certainty of knowledge, whether secured on empiricist or rationalist ground.

Popper also questioned historicism (the doctrine that there are general laws of history) because history, as he saw it, is influenced by the growth of knowledge, and, since knowing is a matter of unpredictable insight, neither the growth of knowledge nor its historical consequences can be systematized. In the political arena he was perhaps best known for his contention, set forth in The Open Society and Its Enemies (1945), that communism and fascism were philosophically linked, and his works, along with those of Milton Friedman and Friedrich von Hayek, provided the theoretical underpinnings for the conservative program of British Prime Minister Margaret Thatcher. Popper was knighted in 1965. His other works include The Logic of Scientific Discovery (1935), The Poverty of Historicism (1957), Objective Knowledge: An Evolutionary Approach (1972), The Self and Its Brain (rev. ed. 1978), and Postscript to the Logic of Scientific Discovery (3 vol., 1981–82).